CVE-2012-3919 in Application Control Engine Module
Summary
by MITRE
The Cisco Application Control Engine (ACE) module 3.0 for Cisco Catalyst switches and Cisco routers does not properly monitor Load Balancer (LB) queues, which allows remote attackers to cause a denial of service (incorrect memory access and module reboot) via application traffic, aka Bug ID CSCtw70879.
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Analysis
by VulDB Data Team • 01/31/2018
The Cisco Application Control Engine ACE module version 3.0 presents a critical denial of service vulnerability that stems from improper monitoring of Load Balancer queues within the network infrastructure. This flaw affects Cisco Catalyst switches and routers, making it particularly concerning for enterprise network environments where these devices serve as critical traffic management components. The vulnerability manifests when the ACE module fails to correctly handle queue monitoring for load balancing operations, creating a condition that can be exploited by remote attackers to disrupt network services.
The technical implementation of this vulnerability involves incorrect memory access patterns that occur during application traffic processing within the ACE module's load balancer functionality. When remote attackers send specially crafted application traffic to the affected devices, the module's queue monitoring mechanism becomes overwhelmed or misconfigured, leading to memory corruption issues. This memory access violation triggers an automatic module reboot, effectively causing a denial of service condition that impacts network availability and connectivity. The vulnerability specifically impacts the ACE module's ability to maintain proper queue state information and process load balancing decisions correctly.
The operational impact of CVE-2012-3919 extends beyond simple service interruption to potentially compromise network stability and business continuity. Organizations relying on Cisco Catalyst switches and routers for application delivery and traffic management face significant risk when this vulnerability is exploited, as the module reboot can occur without any local network disruption, making detection challenging. The remote exploitability means that attackers can trigger the denial of service condition from outside the network perimeter, potentially affecting critical business applications and services. Network administrators must consider the cascading effects this vulnerability can have on dependent services and the broader network infrastructure.
This vulnerability aligns with CWE-129 and CWE-787 in the Common Weakness Enumeration catalog, specifically addressing improper input validation and out-of-bounds write conditions that occur when processing load balancer queue information. From an attack framework perspective, this vulnerability maps to the attack technique T1499.004 in the MITRE ATT&CK framework, representing network denial of service attacks targeting infrastructure components. The vulnerability demonstrates poor resource management and inadequate bounds checking within the ACE module's memory handling routines, creating an exploitable condition that can be triggered through network traffic manipulation.
Mitigation strategies for CVE-2012-3919 should include immediate deployment of Cisco's security patches and updates, which address the queue monitoring logic and memory access handling within the ACE module. Network administrators should implement network segmentation to limit exposure of affected devices and consider disabling unnecessary load balancing features until proper patches are applied. Monitoring should focus on detecting unusual reboot patterns and traffic spikes that might indicate exploitation attempts. Additionally, organizations should review their network architecture to ensure that critical ACE modules are not single points of failure and implement redundant systems to maintain service availability during potential exploitation events.